brooklynwx99

What’s up guys (and gals)? It’s been a little while since I did some analysis on the possible state of this winter, so I decided that since fresh September index values were calculated by NOAA, it would be a good idea to make some rather preliminary forecasts. These are composite-based, as are most of my long-range forecasts, and they are formulated based on this past September’s observed PNA, NAO and AO values. I will be doing these subsequently for October and November with (hopefully) increasing accuracy as we move into December. This September finished with PNA=+1.44, AO=+0.585 and NAO=+1.67. Since positive values were observed for all three major indices, I made a composite of all winters that had their preceding Septembers feature a +AO, +NAO, +PNA trio. That composite looks like this for December-February: One look at this composite and you’ll immediately see a very strong -ENSO signature: a powerful Aleutian ridge and a strongly -PNA with a very cold W US. This made me eliminate the -ENSO winters, as we have a very high chance of experiencing a +ENSO for the upcoming winter. The ENSO has a major impact on a winter’s background forcing, so including -ENSO winters in this composite is almost useless. The vast majority of the years in this composite were -ENSO, and once i finished revising, only 2014-15, 2009-10, and 1997-98 remained. The new composite looked much more +ENSO-esque: The strong Aleutian Low and defined STJ are very common +ENSO characteristics. The super Niño of 1997-98 was included in this composite, so the strength of the Aleutian Low will most likely be less overpowering this winter. I highly doubt we will have too many issues regarding a ENSO driven PAC flow like we would see in this composite. The trough would most likely be focused near the Aleutian Islands rather off the WC. However, I do agree with the blocking shown in the high latitudes, and the incredible 2009-10 winter is definitely an analog for the upcoming winter. The solar minimum that we have entered also bolsters the case for strong polar blocking. Above are the temperature and precipitation departures from normal for the 2014-15, 2009-10, and 1997-98 winters. I agree with the distributions of both sets of anomalies. The temperature anomalies will most likely be colder in general due to the extreme heat of the 1997-98 winter skewing the mean slightly. However, the idea of a warm WC/S Canada makes given sense given the +ENSO background conditions. California and the SE coast/EC look to be much wetter than normal, which is indicative of a defined STJ. Both of these signals point towards a highly active winter along the EC with multiple coastal threats. The high latitude blocking along with a pumped up STJ is a recipe for nor’easters, but as with many +ENSO winters, cold air will might be scarce at times if PAC flow creeps in due to a slight SE displacement of the Aleutian LP. Overall, I remain highly optimistic about this winter due to the analogs that have been deduced from observed conditions along with a possible Modoki +ENSO event and the entrance into a solar minimum. The EC will likely experience an active winter driven by a +ENSO-driven STJ and polar blocking. Cold air might be scarce at times, but injections of polar air are certainly possible if a -EPO forms due to feedback from an Aleutian LP. Coastal storms (both on and off the coast) will probably be the most frequent storm tracks, and a few significant storms are likely. Once October comes to an end, I will revisit my analogs and remake my forecast if needed. For right now, however, I am very optimistic about the state of the upcoming winter.

A useful note: a better factor for determining the impact of a hurricane is integrated kinetic energy (IKE). It takes the size and total energy of the storm into account rather than just winds and pressure, which are the traditional intensity criteria. For example, Sandy was a rather weak storm by wind standards, but its IKE was enormous, second to only Hurricane Isabel. This explains the catastrophic effects it had on the region it impacted. Due to Florence's repeated ERCs, its size will increase, and its IKE will also grow more than it already has. The main takeaway is that even if the winds of this hurricane decrease, that does not mean that its impacts will lessen. It will most likely be the opposite, with more storm surge and subsequent flooding.

The 12z ECMWF also initialized at 965mb, 15mb too high. This would adversely affect the pressure and intensity forecasts later on, so I agree with the idea of a category 4/5 at landfall. As I also said last night, Florence will enter into a favorable region for intensification a couple days before it makes landfall (warmer water, lower shear).

Honestly, one of the worst and most ominous parts of this storm is the stalling, for a couple of reasons. 1) An offshore stall, as shown by the ECMWF, would be absolutely devastating. There would be extreme surge on the NE quadrant of the storm which would persist for days. This is a much worse scenario than 2' of rain and less significant surge. The ocean does much more damage than rain. The mechanism for the prolonged stall has been echoed here for a while. Since Florence is traversing into a massive ML ridge with no troughing in sight, there are no considerable steering currents than can move Florence to the N or E. It is free to remain in the same spot, or have its movement slightly perturbed by its own development or much smaller ML features. 2) One of the biggest problems about stalling is the huge lack of certainty regarding track. Where and when Florence stalls plays an enormous part in practical impacts. If the storm stalls onshore, impacts are slightly lessened due to less onshore flow and rapid pressure rises. In this scenario, rain would become the biggest threat. However, if the storm stalls just offshore (a la 12z ECMWF), the impacts are devastating. Storm surge would become a much larger issue, and the proximity to the shoreline would still allow for copious rainfall and high winds. Also, due to the lack of steering, after the stall, it is nearly impossible to determine where Florence will track. A move S along with restrengthening All in all, the idea of landfall between the Outer Banks and the NC/SC border is beginning to gain more credence, and the impacts from Florence could be catastrophic.

Amazing disco over the last few days in here. You guys are really on top of this storm, it's great to see. I'll offer some of my insight into what I believe will happen with Florence as all of you have over the last few days. Recently, Florence has undergone very rapid development and has become a category 4 hurricane, which is much ahead of schedule in regards to last night's forecast from the NHC. This was partly due to lower levels of wind shear and high levels of upper level divergence throughout the day. Effectively, lower wind shear allows the hurricane to maintain convection around its center of circulation, and UL divergence allows for pressure to drop. Both of these factors are very important for intensification. In the near future, Florence will most likely enter a region of high shear, which could halt its intensification process as it tries to stabilize itself. However, once near the Gulf Stream, shear levels drop near zero. The minimal shear along with anomalously high water temperatures could provide an extremely conducive environment for rapid intensification. This is an ominous scenario for the NC/SC coast. With the lower shear and high water temperatures involved, I can certainly envision Florence becoming a category 5 hurricane before it makes landfall. Personally, I believe that a more southern track is likely due to the extremely anomalous mid level ridge over the W Atlantic. The GFS's northern track does not make too much sense to me, as the GFS has a tendency to overamplify tropical systems, and it keeps them too intense for too long. The 18z GFS was a great example of this. The 18z GFS drops the pressure down all the way to ~900mb, which is extremely low, and the GFS had a habit of dropping pressures too low last year as well. The pressures don't even match up with the maximum sfc winds, which are ~110kt at their maximum. A storm of that pressure usually has winds in excess of 130kt. Also, when hurricanes stall, as this one most likely will, they tend to upwell colder water from the subsurface. This leads to the storm having less heat energy to work with, and it will ultimately weaken. This is one of the consequences of the GFS not being coupled with the ocean: its pressure forecasts are nonsensical, and they have an adverse effect on the forecast. Overall, I believe that slightly N of the NC/SC border has the highest risk for landfall, and Florence will most likely be a category 4 hurricane or stronger when reaches the coast due to the factors I mentioned above. The combination of extremely strong winds, possibly devastating storm surge, flooding rain, and very high swells (possibly +20ft!) could make this a potentially catastrophic event for the NC/SC coast.

My advice: when you see a cutoff ridge of that magnitude, it will overpower pretty much anything. The GFS's idea of plowing the storm through the ridge is not reliable due to its overamplification bias, and the storm will most likely move around the ridge. 594+dm ridges are nothing to mess around with. I see this as a strong threat for the EC right now with the underlying atmospheric conditions present. The ridge will force it into the coast. Highly anomalous ridges near Bermuda are ominous in regards to possible US landfall.

I thought that since winter is somewhat approaching, it would be wise to offer some tidbits that could help us crack the 2018-2019 season. One of them in particular is the solar minimum that we are in the midst of. The number of sunspots has dropped to ~0 in the past few months, indicating that we have truly entered into a solar minimum. This has some implications for the winter(s) ahead, primarily in regards to blocking. The map above shows a composite of years where a solar minimum was either imminent or in progress. As you can see, the extreme blocking over Greenland is a huge feature in this composite. Last winter had the power of a strongly -NAO/AO on full display with four nor'easters in less than a month's time. The upcoming winter will feature a deep solar minimum, which leads me to believe that the ECMWF seasonal forecasts might very well have credence. A -NAO/AO is certainly in the cards yet again. El Nino looks be a likely scenario during the upcoming winter as well. A moderate El Nino would provide a strong STJ, which bodes very well given the heightened chance for high-latitude blocking due to the solar minimum. This combination could be extremely conducive for winter weather in the NE/MA regions. All in all, I see no glaring negative signs about this winter so far. In fact, the impacts of a solar minimum and moderately +ENSO could become the background factors that produce a memorable winter. However, the behaviors of the ENSO and other teleconnections in October and November will be crucial in deciding the eventual flavor of this winter. As of now, I'm very cautiously optimistic.

I remember a couple years ago when we were sitting pretty at 15-20 games ahead in August, but we went on an awful run as the Blue Jays rallied. We ended up placing 2nd in the AL East and then lost the WC game. A team could change its fate in two weeks in late summer. The only "bad start" would be if the Yankees were like 4-12 at this juncture, because then you have an actual hole to crawl out of. .500 is fine up until July, practically speaking. Also, why even watch baseball if you're gonna give the year up in 3 weeks?

Makes no sense. If this was September and the Yanks were under .500, it would be a different story. 150 games left.

is this a troll post

Also, last year the Yankees had two months under .500 (June and August), so there is a ton of room for error given the length of the season. Doesn’t even matter if we end April under .500 (which is extremely unlikely IMO) because of the huge season. We were also only 9 games above .500 going into September and were one game away from the WS. In other words, the record really doesn’t matter now. Just gotta let the pieces click.

It would be much more concerning if the Yanks got blown out in games they lost and had to come back to win games. Instead, they blow out teams in their wins and have suffered comeback losses, which are easily avoidable. It’s 10 games in and although the losses are more painful because they’re close, the team will more than likely make a big run at some point. I’m not worried. Talk to me in July.

"The NAO is an overrated index" Absolutely gorgeous evolution, and it was driven by the -NAO clogging up the flow, allowing the energy to amplify. It's no coincidence that the EC experienced four nor'easters in a month's time. I think the next few years will be very fun, as we will be in a solar minimum and possibly enter into a -NAO regime.

Absolutely classic. NYC, W LI and the Jersey Coast are going to get destroyed over the next several hours.

Some pictures from earlier at PSU. Got 5” here, which was a nice treat. Wish i was back home in Brooklyn though, you guys are getting crushed! note: there was accumulation on untreated pavement, but they salt the hell out of everything here